Asphalt Mixture of Stress Relief Layers on Concrete Pavement Overlays

prevent reflection cracks on asphalt pavement

1. Description

    Stress Relief Asphalt Layers is arranged between the asphalt concrete surface and the existing cement concrete pavement. The high elastic stress absorption layer plays the role of absorbing stress, waterproofing and sealing water, and preventing reflection cracks. Overlaying stress-absorbing layer has achieved certain effect in preventing reflection cracks in asphalt pavement. Reflective cracks are a common form of damage on asphalt pavements. Reflective cracks are mainly reflected from cracks and construction joints in semi-rigid base or other lower bearing layers.
 
    About 0.5% of high elastic anti-cracking additive is added to the high-elastic stress-absorbing layer. The high-elastic anti-cracking additive is similar to a rubber band and has good elastic recovery ability, which increases the ability of the stress-absorbing layer to absorb shear stress. The protection of the asphalt surface layer is stronger.
 
 

Reflection cracks
 
    ZTS Stress Relief Asphalt Layers between the cracked structure layer and the asphalt overlay is an effective measure to prevent reflection cracks. It is an asphalt mixture with strong adhesion, impermeability, and good interface bonding performance, can deform with the deformation of the base layer, and has excellent self-healing ability.
 

Advantages of Stress Relief Asphalt Layers​:

• Good adhesion, low temperature resistance and fatigue resistance.
• Resistance to high temperature deformation.
• The construction workability of the asphalt mixture is better.
• Construction is more convenient by using ordinary asphalt paver.
• No special modified bitumen and special equipment are needed in the production and construction process, the cost is more lower.
• Environmental protection, no restrictions on asphalt paving.

2. Special additive for Asphalt Stress Absorbing Membrane Interlayer

    ZTA-VE asphalt additive are a new type of composite asphalt additive developed by Beijing Zhongtian Road Tech Co. Ltd. It integrates the technical characteristics of high viscosity, high elasticity, wide temperature range, and warm mixing to improve the crack resistance and fatigue resistance of road materials, reduce the difficulty of road construction, energy saving and environmental protection.
 

Table 1 Technical indicators of VE high-elastic anti-cracking additive

3. Production and Construction of Asphalt Mixture of Stress Relief Asphalt Layers

    When mixing ZTS mixture, firstly add all grades of aggregate and VE high-elasticity anti-cracking additive for dry mixing, then add bitumen and mineral powder, and the mixing time is not less than 45 seconds, of which ZTA-VE additives and aggregate are dry mixed for 10 seconds. The temperature control requirements are shown in Table 2.

Table 2 Temperature control table for mixing and construction

The paving speed of asphalt paver is 3m-6m/min.
The repeat compacting roller needs to be rolled closely with the initial compacting roller.

The initial compacting adopts 13 tons - 15 tons of drum rollers
The repeat compacting adopts 20 tons - 26 tons rubber wheel rollers
The final compacting adopts below 11 tons of drum roller
(The vibration is not turned on during the rolling process)

Traffic can be opened only when the road surface temperature is lower than 50°C

4. Technical comparison of ZTS Stress Relief Asphalt Layers & conventional rubber asphalt stress absorption layer

5. Company information

 
    Beijing Zhongtian Road-Tech Co.,Ltd. is the Board of Directors of China Transportation Association and Transportation Committee of China Technological Market Association, with expert technical R&D team, continuous innovation ability, rich engineering experience and sufficient capacity. Also we participated in designated road material industry standard certificates.